Concerns with his politics aside, I do think there's a truth to what he's talking about here, and that he is just spelling out the reality that developers are, or shortly will be, facing. For many this will be deeply uncomfortable to hear.
It is notable that his perspective in this talk is very much from a developer-user side rather than someone who is responsible for the framework itself. That surprises me, and I suspect it is not a good omen for Rails.
For all of this embrace of agentic development, there is nothing here on how they are adapting the framework for this new agentic development reality. Agents do currently work well with Rails, but there's nothing here pushing things forward as best as I can see.
I know for my own projects I've largely moved to Elixir/Phoenix, for similar reasons to his use of Rust... I didn't want to have to learn it, but now I don't have to and I get to benefit from its strengths.